Oral appliance



FIG. 1 is a rear and bottom perspective view of an oral appliance showing my new design;

FIG. 2 is a front and top perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a front elevation thereof;

FIG. 6 is a rear elevation thereof;

FIG. 7 is a right side elevation thereof; and,

FIG. 8 is a left side elevation thereof.

The claimed ornamental design is shown in solid lines in the drawings. The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for an oral appliance, as shown and described. 